Phantom limb pain and stump pain are common sequela of amputation. Most recent studies estimate 50-75% of amputees suffer from phantom pain early after amputation. Persistent phantom pain is difficult to treat and often worsens over time. Stump pain is less common and often decreases with time. The purpose of this study is to determine the efficacy of intravenous lidocaine and morphine infusions as compared to placebo on phantom and stump pain after amputation of extremities using a double-blind cross-over randomized protocol. In addition, this study will examine whether these diagnostic infusions can serve as a predictive tool to evaluate the potential success of oral chronic therapy with slow release opioids and mexiletine.